Housing forming method and housing structure

ABSTRACT

An object of the invention is to provide a method for easily molding projections on an end edge along an opening in a housing which project towards an opposite side of the end edge to the opening, and to provide a housing structure related to the method.  
     The invention relates to a method for molding a housing, including molding an end edge ( 6 ) which extends outwardly of an opening ( 4 ) in a housing ( 1 ) such that a closing member ( 5 ) for closing the opening ( 4 ) is locked thereto by using a first mold ( 30 ) having a grating-like portion and a second mold ( 40 ) adapted to alternately mesh with the grating-like portion of the first mold ( 30 ), and forming an projection ( 28 ) which projects towards an opposite side to the opening ( 4 ) on an outer side of the end edge ( 6 ) by drawing out the grating-like portion of the first mold ( 30 ) which penetrates the end edge ( 6 ) towards the opening ( 4 ) side which is opposite to an end portion of the grating-like portion and drawing out the second mold ( 40 ) from the end edge ( 6 ) position outwardly of the housing ( 1 ).

TECHNICAL FIELD

[0001] The present invention relates to a method for molding a housingand a housing structure, and more particularly to a method for molding alamp housing used for a headlamp, etc., and a lamp housing structure.

BACKGROUND ART

[0002] In an example of a conventional headlamp of a vehicle, as shownin FIGS. 9 and 10, a bulb 2 and a reflector 3 are disposed in theinterior of a lamp housing 1 made of a resin, and a lamp lens 5 isassembled over an opening 4 formed in the lamp housing 1 on a sidethereof which faces the front of the vehicle. A packing 8 is interposedbetween an end edge 6 of the lamp housing 1 by which the opening 4 isdefined and an end edge 7 of the lamp lens 5, and the lamp housing 1 andthe lamp lens 5 are locked together by clips 9 which are each formed ofa steel spring plate and which are disposed along an outercircumferential direction of the housing and lens at appropriateintervals.

[0003] In order to ensure the locking by the clips 9, the followings areneeded.

[0004] Firstly, a projection 10 which projects towards the rear in alongitudinal direction of the vehicle is formed on the end edge 6 of thelamp housing 1, and a projection 11 which projects towards the front inthe longitudinal direction of the vehicle is formed on the end edge 7 ofthe lamp lens 5. A clip 9 is then brought into engagement with theseprojections 10, 11. In this way, the locking by the clip 9 can beensured.

[0005] Incidentally, when molding the lamp housing 1, in order to form arecessed portion in which the packing 8 is disposed in the end edge 6 ona side thereof which faces the front of the vehicle, a mold 12 indicatedby a two-dot chain line needs to be drawn towards the front side of thevehicle (leftwards in FIG. 10) as indicated by an arrow A. On the otherhand, in order to form the projection 10 on the end edge 6 on a sidethereof which faces the rear of the vehicle, a mold 13 indicated by thetwo-dot chain line needs to be drawn towards the rear side of thevehicle (rightwards in FIG. 10) as indicated by an arrow B.

[0006] There may be a case in which a mounting seat surface of the lamphousing 1 or a reinforcement rib 14 (hereinafter, simply referred to asa rib 14) is provided on an outer circumferential wall surface of thelamp housing 1 in the vicinity of an end of the projection 10 on the endedge 6 which faces the rear of the vehicle. As this occurs, while theprojection 10 and the rib 14 are desired to be molded at the same time,since the rib 14 is situated on the drawing path of the mold 13 (in thedirection indicated by the arrow B), the mold 13 cannot be drawn asdesired, and therefore, it is extremely difficult in reality to form theprojection 10 and the rib 14 at the same time. Thus, the degree offreedom in designing the lamp housing 1 is largely limited. Also, thenumber of molds is increased due to the provision of the rib 14, thisleading to a problem that the production costs are increased.

[0007] An object of the invention is to provide a method for easilymolding a projection on an end edge defining an opening in a housing,which projects towards an opposite side of the end edge to the opening,and to provide a housing structure related to the method.

DISCLOSURE OF THE INVENTION

[0008] To this end, in a method for molding a housing according to theinvention, an end edge (6) which extends outwardly of an opening (4) ina housing (1) such that a closing member (5) for closing the opening (4)is locked thereto is molded by using a first mold (30) having agrating-like portion and a second mold (40) adapted to alternately meshwith the grating-like portion of the first mold (30), and an projection(28) which projects towards an opposite side to the opening (4) isformed on an outer side of the end edge (6) by drawing out thegrating-like portion of the first mold (30) which penetrates the endedge (6) towards the opening (4) side which is opposite to an endportion of the grating-like portion and drawing out the second mold (40)from the end edge (6) position outwardly of the housing (1).

[0009] Consequently, according to the method for molding a housingaccording to the invention, the second mold for molding the projectionis drawn out from the end edge position of the housing outwardly of thehousing. Namely, since a drawing to the opposite side to the opening isnot needed, in addition to the formation of the projection, an extendingmember such as a rib can easily be provided on the outer circumferentialwall surface of the housing close to the projection on the opposite sideto the opening.

[0010] In addition, in a structure according to the invention for ahousing (1) in which a closing member (5) is engaged by an engagementmember (9), the structure has an opening (4) closed by the closingmember (5), an end edge (6) extending from the opening (4) outwardly ofthe housing (1) and a locking portion (20) formed on the end edge (6),the locking portion (20) is provided with a plurality of through holes(22) which pass through the locking portion (20) from a side thereofwhich face the opening to an opposite side thereof to the opening, aplurality of vertical walls (23) which divide the adjacent through holesand a lateral wall connecting the vertical walls (23) at one endsthereof, the vertical walls (23) are formed shorter than the lateralwall (24) on the opposite side thereof to the opening, and the lateralwall (24) has notches (27) formed therein on the opposite side to theopening and at locations which confront the vertical walls (23) andprojections (28) formed thereon on the opposite side to the opening andat locations which confront the through holes (22), respectively.

[0011] Consequently, according to the housing structure, since theprojections (28) are formed on the end edge (6) which project to theopposite side of the end edge (6) to the opening, the closing member (5)can securely locked to the end edge (6) of the housing by bringing theengagement members (9) into engagement with the projections (28).

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a vertical cross-sectional view of a main part of a lamphousing adopting an embodiment of the invention (corresponding to aportion indicated by X in FIG. 9);

[0013]FIG. 2 is an enlarged development as seen in a direction indicatedby arrows II-II in FIG. 1;

[0014]FIG. 3 is an enlarged vertical cross-sectional view as seen in adirection indicated by arrows III-III in FIG. 2;

[0015]FIG. 4 is an enlarged vertical cross-sectional view as seen in adirection indicated by arrows IV-IV in FIG. 2;

[0016]FIG. 5 is an enlarged vertical cross-sectional view taken alongthe line V-V in FIG. 1;

[0017]FIG. 6 is an enlarged perspective view of the main part of thelamp housing;

[0018]FIG. 7 is an explanatory view of the embodiment taken along theline VII-VII in FIG. 5 (illustrating a mated state of molds);

[0019]FIG. 8 is an explanatory view of the embodiment taken along theline VIII-VIII in FIG. 5 (illustrating a mated state of the molds);

[0020]FIG. 9 is a schematic vertical cross-sectional view of aconventional lamp housing 9; and

[0021]FIG. 10 is an enlarged view of an X portion in FIG. 9.

MODE FOR CARRYING OUT THE INVENTION

[0022] An embodiment of the invention will be described below with likereference numerals being given to like portions to those of theconventional housing example that has been described above.

[0023] Firstly, a lamp housing 1 constituting a housing will be brieflydescribed according to FIG. 1.

[0024] In the lamp housing 1 made of a resin for an automotive headlamp,locking portions 20 each having an appropriate width are formed in acircumferential direction on an outer side of an end edge 6 of anopening 4 formed in the lamp housing 1 on a side thereof which faces thefront of a vehicle. The locking portions 20 are provided along the outercircumference of the lamp housing 1 with an appropriate interval beingprovided therebetween. A lamp housing mounting rib (an extending member)21 is formed on a lower surface of the lamp housing 1 close to a side ofthe locking portion 20 facing the rear of the vehicle (the right-handside in FIG. 1) which is an opposite side of the locking portion 20 tothe opening.

[0025] Next, the locking portion 20 will be described based on FIGS. 2to 6.

[0026] Each locking portion 20 has on an outer side of the end edge 6four square holes 22 constituting a plurality of through holes passingtherethrough from the opening side of the locking portion 20 to theother side. By this, the locking portion 20 has vertical wall portions23 constituting a plurality of vertical walls that divide the respectivesquare holes 22 provided in parallel, a lateral wall portion 24constituting a lateral wall that connects lower ends of the respectivevertical wall portions 23, and side wall portions 25 connecting bothside edges of the lateral wall portion 24 and an outer circumferentialsurface of the lamp housing 1.

[0027] The vertical wall portion 23 is set shorter than the lateral wallportion 24 on the opposite side thereof to the opening, and asubstantially rectangular parallelepiped space 26 is defined on the sideof each vertical wall portion 23 which is opposite to the opening (onthe side thereof which faces the rear of the vehicle). In addition, anotch 27 is provided at a position below the space 26 and correspondingto the vertical wall portion 23, whereby a plurality of projections 28which project towards the opposite side to the opening are formeddiscontinuously at lower positions on the opposite side to the openingso as to correspond to the square holes 22, respectively.

[0028] Thus, in the housing structure according to the embodiment of theinvention, clips 9 which constitute engagement members are brought intoengagement with projections 11 formed on an end edge 7 of a lamp lens 5which constitutes a closing member and the projections 28 formed on thelocking portions 20 provided on the outer surface of the end edge 6 ofthe lamp housing 1 in such a manner as to straddle therebetween, wherebythe end edge 7 of the lamp lens 5 can be securely and easily locked tothe end edge 6 of the lamp housing 1 with a packing 8 being heldterebetween.

[0029] Next, a method for molding the locking portions 20 on the endedge 6 will be described according to FIGS. 7 and 8.

[0030] A mold 30 which constitutes a first mold has a central portion 31for molding an internal surface of the lamp housing 1, an end faceportion 32 for molding an opening-side end face of the end edge 6 of thelamp housing 1, a plurality of square pillar portions 33 which projectfrom the end face portion 32 and which constitute pillar-like portionswhich correspond to a molded shape of the square holes 22, void portions34 corresponding to a molded shape of the respective vertical wallportions 23, and a mold registering surface 35.

[0031] The square pillar portions 33 and the void portions 34 aredisposed in parallel alternately, and the four square pillar portions 33constitute a grating-like portion which looks like teeth of a comb.

[0032] A mold 40 which constitutes a second mold has square pillarportions 41 which correspond to molded shapes of the spaces 26 rearwardof the vertical wall portions 23 and the notches 27 in the lateral wallportion 24, an end face 42 for molding an outer circumferential surfaceof the lamp housing 1 which is situated on a side thereof which facesthe front of the vehicle, an end face 43 for molding a surface of themounting rib 21 which faces the front of the vehicle and a lower surfacethereof, and mold fitting surfaces 44, 45.

[0033] A mold 50 has an end face 51 for molding an outer surface of thelamp housing 1 on the rear side of the vehicle, an end face 52 formolding a side surface of the mounting rib 21 which faces the rear ofthe vehicle and a mold fitting surface 53.

[0034] In molding the lamp housing 1, while these molds 30, 40, 50 areassembled and fastened together as shown in FIGS. 7 and 8, as thisoccurs, the square pillar portions 41 of the mold 40 are made toalternately mesh with end portions of the square pillar portions 33 ofthe folding mold 30. In other words, the mold 30 and the mold 40 areassembled together in such a manner that the square pillar portions 41which constitute elongated protruding portions protrude into the voidportions 34 formed between the adjacent square pillar portions 33.

[0035] In the event that a lamp housing 1 is formed from this state, themain portions of the locking portion 20 are molded as follows. Namely,square holes 22 are formed by the square pillar portions 33. Verticalwall portions 23 are molded by the void portions 30 and the squarepillar portions 41. A lateral wall portion 24, projections 28 andnotches 27 are formed by the square pillar portions 33, the voidportions 34 and the square pillar portions 41.

[0036] In addition, the respective molds are removed from each other asfollows. Namely, the mold 30 which has the square pillar portions 33passing through the locking portion 20 from the opening side to theother side on the outer surface of the end edge 6 is drawn to theopening side which is opposite to the end portions of the square pillarportions 33 (in a direction indicated by an arrow A, the mold 50 isdrawn to the side which is opposite to the opening (in a directionindicated by an arrow B), and the mold 40 is drawn from the positionwhere the end edge 6 is formed to a direction towards an external sideof the lamp housing 1 (in a downward direction in the drawing) whichintersects with a direction indicated by an arrow A at right angles, asindicated by an arrow C. Here, as shown in FIG. 8, since the squarepillar portions 41 of the mold 40 are provided in such a manner as toextend directly downwardly from the void portions in the mold 30 to alocation which constitutes the lateral wall portion 24 of the lockingportion 20 in the lamp housing 1, even if the projections 28 are molded,the mold 40 can be drawn downwardly without being disrupted by theprojections 28.

[0037] By this, the locking portion 20 having the plurality ofprojections 28 which protrude to the opposite side to the opening caneasily be molded on the end edge 6. In addition, since there is causedno specific problem with molding the mounting rib 21 which extendsoutwardly of the lamp housing 1, the mounting rib 21 can be molded atthe same time that the locking portion 20 is molded.

[0038] Namely, as has been described heretofore, according to the methodfor molding a housing according to the embodiment of the invention, evenif the projections 28 are molded on the locking portion 20 whichprotrude to the side thereof which is opposite to the opening, since themold 40 for molding the projections 28 is drawn in the downwarddirection which intersects with the mold 30 at right angles, in otherwords, there is no case where the mold 40 is drawn to the side which isopposite to the opening, an extending member such as the mounting rib 20can formed in such a manner as to be close to the side of the lockingportion 20 which faces the rear of the vehicle easily andsimultaneously.

[0039] Consequently, the degree of freedom in laying out the headlampcan be increased at the same time that the degree of freedom indesigning the lamp housing 1 can be increased. In addition, the increasein the number of molds can be suppressed, whereby the production costsof the lamp housing 1 can simply be decreased. Moreover, the clips 9which have been in use conventionally can be used as they are, andtherefore, it is characteristic that a tremendous advantage can beprovided in practical use.

[0040] Note that while the embodiment has been described as the lockingportions 20 being provided downwardly of the end edge 6, the inventionis such as to be similarly established in a case where the lockingportions 20 are formed not only downwardly but also outwardly of the endedge 6 including sideward or upwardly of the end edge 6.

[0041] In addition, the numbers of the square holes 22 and the verticalwall portions 23 in the locking portion 20 can be selected appropriatelyaccording to the width of the clip 9 which is brought into engagementwith the projection 28.

[0042] Furthermore, in case the invention is applied, in addition to thelamp housing of the headlamp, to other lamps on the vehicle such as arear stop lamp and a combination lamp as done in the embodiment, anequivalent function and advantage to those provided in the embodimentcan also be provided.

[0043] Furthermore, the invention can be applied to molding not only thelamp housings but also housings in general.

INDUSTRIAL APPLICABILITY

[0044] As has been described heretofore, the invention is useful as themethod for molding the lamp housing for use for the headlamp and thestructure for the lamp housing.

1. A housing molding method comprising; by using a first mold having agrating-like portion and a second mold adapted to alternately mesh withthe grating-like portion of the first mold, molding an end edge whichextends outwardly of an opening in a housing such that a closing memberfor closing the opening is locked thereto; and forming a projectionwhich projects towards an opposite side to the opening on an outer sideof the end edge by drawing out the grating-like portion of the firstmold, which penetrates the end edge, towards the opening side which isopposite to an end portion of the grating-like portion and drawing outthe second mold from the end edge position outwardly of the housing. 2.The housing molding method according to claim 1, wherein the first moldhas a plurality of pillar-like portions which pass through the end edgeand void portions formed between the pillar-like portions, thegrating-like portion is formed by providing the pillar-like portions andthe void portions alternately, and the second mold has a plurality ofprojecting portions which project into the void portions.
 3. The housingmolding method according to claim 2, wherein the projection is formed bya space surrounded by the pillar-like portions of the first mold and theprojecting portions of the second mold.
 4. The housing molding methodaccording to claim 1, further comprising: providing a third mold adaptedto be assembled to the second mold on an opposite side to the opening;and forming an extending member which extends outwardly of the housingby drawing the third mold to the opposite side to the opening.
 5. Thehousing molding method according to claim 1, wherein the housing is alamp housing, and the closing member is a lamp lens.
 6. A structure fora housing in which a closing member is engaged by an engagement member,characterized by comprising: an opening closed by the closing member; anend edge extending from the opening to the closing member; and a lockingportion formed on the end edge; wherein the locking portion is providedwith a plurality of through holes which pass through the locking portionfrom a side thereof which face the opening to an opposite side thereofto the opening, a plurality of vertical walls which divide the adjacentthrough holes and a lateral wall connecting the vertical walls at oneends thereof, the vertical walls are formed shorter than the lateralwall on the opposite side thereof to the opening, and the lateral wallhas notches formed therein on the opposite side to the opening and atlocations which confront the vertical walls and projections formedthereon on the opposite side thereof to the opening and at locationswhich confront the through holes, respectively.
 7. The structure for ahousing according to claim 6, further comprising an extending memberwhich extends outwardly of the housing on a side of the end edge whichis opposite to the opening.
 8. The structure for a housing according toclaim 6, wherein the housing is a lamp housing, and the closing memberis a lamp lens.